You might not have time for a "real" second job, but I bet you can find various odd jobs. This is a great way to earn income on YOUR schedule because you can take or refuse jobs as needed, I'm a few years older than you, but also married, no kids. I've had great luck babysitting, housesitting/ dog sitting, (see my blog entry on
the subject here. Let people know you are looking for additional income, you'll be amazed what might turn up. I 've been offered $20 / hour to rake leaves!!
Also, start purging your house of stuff you're not using and sell it a Craig's List, ebay, half.com etc.
Lastly, start tracking everything you earn/ spend. Your computer might already have MS money. Otherwise, just use Excel or a pen and pencil. It will really open your eyes up to where your money is going.
Good luck!